Most prior art hardware approaches for converting an X-Y position voltage into corresponding range and bearing readings have employed modulators to produce signals that yield a phase angle from which the bearing can be determined. These approaches have generally been exclusively analog, relying on conventional clamping and chopper circuits to obtain bearing output. A number of these techniques have utilized successive approximation methods requiring numerous feedback and comparison networks which slow down and complicate the converter circuitry. Further, such prior art analog approaches have lacked the versatility, reliability, and adaptability which a digitally designed converter would provide.
It is, therefore, an object of the present invention to convert analog rectangular coordinate inputs into digital range and bearing (polar) form in a simple, highly reliable fashion without using valuable computer time.
It is a further object of the present invention to examine the operational signs of the analog inputs to determine into which quadrant the bearing belongs and to provide multiplexing circuitry for appropriately channeling angle information to produce a bearing output located in the proper quadrant.